1. Field of the Invention
This invention relates to means for coupling pipe segments and the like and more particularly, but not by way of limitation, to the use of a plurality of circular disc members removably inserted in cooperating grooves between the segments to be coupled for locking the said segments in coupled engagement.
2. Description of the Prior Art
Heretofore, the means for coupling pipe segments by the use of telescoping members was by locking said members in engagement by providing cooperating grooves between the telescoping members and filling those grooves with ball members as taught in the patent to Rusche, U.S. Pat. No. 3,365,220 issued Jan. 23, 1968 and entitled "JOINT FOR COUPLED PILE DRIVING MANDREL". This locking means was satisfactory in that the ball members were relatively inexpensive and easily inserted and removed from the grooves. The above locking member was also satisfactory in cases where small loads were required either in tension or compression. However, when the above coupling was subjected to high loading it was found that since the ball members made contact at the groove joints only at one point on each ball, the balls left imprints along the groove edges or the rolling surfaces of the balls became deformed thereby making removal of the balls difficult and often causing permanent damage to the grooves themselves.
A solution to one of these problems was proposed in the patent to Gross et al, U.S. Pat. No. 3,507,532 issued Apr. 21, 1970 entitled "CLOSURE MEANS". Instead of using balls for the locking members, Gross et al utilized a plurality of lock wire segments, each of which were shaped to fit the curvature and cross sectional shape of the grooves. This solution provided substantially continuous surface contact along the edges of the grooves which provided even loading and avoided the deformation or tracking problems present with the use of ball members.
However, with the Gross et al device two major problems are readily apparent. The first problem is the necessity of sliding each segment into the cooperating grooves which is much more difficult as opposed to rolling ball bearings into the grooves. Secondly, it is also apparent that the manufacturing of the lock wire segment will be relatively difficult and expensive since each application of couplings having different diameters will require lock wire segments having a matching radius or curvature.